There are various known related arts for controlling a network.
For example, in a network, each node obtains a link status and a state between nodes by periodically exchanging a message such as Link Layer Discovery Protocol (LLDP) and Keep Alive. In a system that centralizedly manages such a network, a controller centralizedly managing a network receives, from each node obtaining a link status and a state, a message that notifies of the status and the state. In this manner, the controller obtains a status and a state of a network in a range under management of the own controller.
In a controller as described above, an increased number of nodes in a network causes more notification messages to a controller, which increases a load on the controller.
PTL 1 discloses a monitoring system coping with such a load increase. A center device of the monitoring system in PTL 1 determines, taking into consideration increase and decrease of a processing load in accordance with the number of terminal devices, a receiving time interval in such a way as to implement a message receiving interval in accordance with a processing capability of the own device. The receiving time interval indicates an interval at which the own center device receives a message from each of the terminal devices.
Further, in PTL 1, a transmitting interval of a terminal device is set in such a way that a terminal device having a higher frequency of occurrence of request information from the center device has a shorter transmitting interval. With this setting, the center device preferentially monitors a terminal device that the center device desires to intensively monitor.
In addition, there is a related art for controlling a network as follows.
PTL 2 discloses an information sharing space provision system. The information sharing space provision system in PTL 2 includes the following configurations. First, a synchronization control information management unit, an object information management unit, and an invitation unit of each of a plurality of terminals reflect control of a group to a storage unit of each of the terminals. Herein, examples of control of a group include an operation on a shared object, member addition, and group creation which are performed between the terminals. Secondly, a message control unit of each of the terminals notifies another terminal that constitutes a group, of a processing content. Thirdly, the terminal having received the notification reflects the notification in the same way. In this manner, the information sharing space provision system shares information within a group formed of arbitrarily selected members.
PTL 3 discloses a mobile communication system that transmits and receives data by using a shared channel. A base station device of the mobile communication system in PTL 3 includes the following configurations. First, a within-range check signal generating means generates a within-range check signal for a first mobile station device among mobile station devices present in an area of coverage. Herein, the first mobile station device is a mobile station device shifted to an intermittent reception status and/or an intermittent transmission status. In addition, the within-range check signal is a signal for checking that the first mobile station device is present in an area. Secondly, a within-range check signal transmission control means executes control in such a way as to transmit the within-range check signal to a second mobile station device among the shifted first mobile station devices. The second mobile station device is a mobile station device in which time over a within-range check signal transmission cycle elapses in the intermittent reception status and/or the intermittent transmission status. By including these configurations, the base station device determines that a mobile station device is within a range when a response to a within-range check signal can be received from the mobile station device to which the within-range check signal is transmitted.
PTL 4 discloses a Device Assisted Service (DAS) for protecting network capacity. First, the DAS monitors a network service usage activity of a communications device in network communication. Secondly, the DAS classifies the network service usage activity for the purpose of differential network access control for protecting network capacity. Thirdly, the DAS associates, based on the classification of the network service usage activity, the network service usage activity with a network service usage control policy in order to facilitate realizing differential network access control for protecting network capacity.